class TransformContext {
  List<mat4> matrices;
  
  mat4 get top() => matrices.last();
  
  TransformContext() {
    matrices = [new mat4.identity()];
  }
  
  void push(mat4 item) {
    matrices.add(item);
  }
  
  mat4 pop() {
    return matrices.removeLast();
  }
}
